I personally like GHRP 2 and 6. I have not used GRF but I have heard good things from others. The amount of GH produced will vary from person to person, depending on your personal ability to produce GH. I have used GHRPs at 200mcg and like them there. I've used more and less, but 200 is where I like to be. There is a difference between exogenous GH and these peps though. GH will have a longer life in your body, where as the secretagogues produce a pulse that lasts more like 30 min. Because of this, I would use the secretagogues more often, 3x a day. If you have the funds to run some GH on top of your program, it will only help! IME, 2iu of high quality GH will make a difference in fat loss alone. Add in the other peps and you'd have a good program.
2iu First thing in the moring.
secretagogues 6 hours later, again post workout(assuming you train a few hours later), then again before bed